> GetWarnings() changes the format of the output warning string based on a
> passed-in string argument that can be set to "gui" or "statusbar".
> Change the argument to a bool `verbose`:
>
> - there are only two types of behaviour, so a bool is a more natural
> argument type
> - changing the name to 'verbose' does not set any expectations for the
> how the calling code will use the returned string (currently,
> 'statusbar' is used for RPC warnings, not a status bar)
> - removes some error-handling code for when the passed-in string is not
> one of the two strings expected.
This is a partial backport of Core PR17750 [2/3]
https://github.com/bitcoin/bitcoin/pull/17750/commits/492c6dc1e742a62599dc6d5ba6c3896825b5144f